T cells modulate glycans on CD43 and CD45 during development and activation, signal regulation, and survival

Abstract

Glycosylation affects many essential T cell processes and is intrinsically controlled throughout the lifetime of a T cell. CD43 and CD45 are the two most abundant glycoproteins on the T cell surface and are decorated with O- and N-glycans. Global T cell glycosylation and specific glycosylation of CD43 and CD45 are modulated during thymocyte development and T cell activation; T cells control the type and abundance of glycans decorating CD43 and CD45 by regulating expression of glycosyltransferases and glycosidases. Additionally, T cells regulate glycosylation of CD45 by expressing alternatively spliced isoforms of CD45 that have different glycan attachment sites. The glycophenotype of CD43 and CD45 on T cells influences how T cells interact with the extracellular environment, including how T cells interact with endogenous lectins. This review focuses on changes in glycosylation of CD43 and CD45 occurring throughout T cell development and activation and the role that glycosylation plays in regulating T cell processes, such as migration, T cell receptor signaling, and apoptosis.

Basic Motifs Target PSGL-1, CD43, and CD44 to Plasma Membrane Sites Where HIV-1 Assembles

“…Therefore, further analyses of the roles played by the polybasic sequences will likely help with the development of a new strategy to improve the targeting specificity of lentiviral vectors via pseudotyping. It is known that PSGL-1, CD43, and CD44 participate in adherence, motility, cell-cell contact, and cell signaling events in lymphocytes (48)(49)(50)(87)(88)(89)(90). However, although a mechanism promoting the specific recruitment of these proteins to assembly sites does exist, as revealed in this study, it is unknown whether these proteins play important roles in HIV-1 replication.…”

Hypoxia: The Force that Drives Chronic Kidney Disease

“…356,357 The extracellular domains of both CD43 and CD45 are heavily decorated with O-linked and N-linked carbohydrate moieties that often terminate in sialic acid. 358 The strong negative charge conferred by this sialic acid, coupled with abundance and length, allow CD43 and CD45 to prevent leukocyte adhesion. When leukocytes are activated, there is a downregulation of CD43 and CD45 along with a reduction in their sialylation and a concomitant up-regulation of the proadhesive β2-integrin family.…”

“…When leukocytes are activated, there is a downregulation of CD43 and CD45 along with a reduction in their sialylation and a concomitant up-regulation of the proadhesive β2-integrin family. [358][359][360][361][362][363] The induction of this reciprocal expression of anti-adhesion and pro-adhesion forces results in leukocytes acquiring an adhesive phenotype capable of extravasation and infiltration into organs such as the kidney (figure 2).…”

Functional Evaluation of Activation-dependent Alterations in the Sialoglycan Composition of T Cells

“…Therefore, control of T-cell activation is important to optimize the immune response. Upon activation, T cells undergo a variety of changes in glycosylation patterns (1)(2)(3)(4)(5)(6)(7), but the functional roles of such changes remain unclear (8). It is necessary to understand activation-dependent changes in glycosylation not only to define the mechanism of T cell-mediated immune regulation but also to support efforts to artificially modulate immune responses because glycans are located in the outermost regions of cells and are highly accessible.…”